The disclosure relates to a wireless power transmission technology. In more particular, the disclosure relates to a wireless power receiver and a wireless power transferring method capable of maximizing the power transmission efficiency by using resonance.
A wireless power transmission or a wireless energy transfer refers to a technology of wirelessly transferring electric energy to desired devices. In the 1800's, an electric motor or a transformer employing the principle of electromagnetic induction has been extensively used and then a method for transmitting electrical energy by irradiating electromagnetic waves, such as radio waves or lasers, has been suggested. Actually, electrical toothbrushes or electrical razors, which are frequently used in daily life, are charged based on the principle of electromagnetic induction. The electromagnetic induction refers to a phenomenon in which voltage is induced so that current flows when a magnetic field is varied around a conductor. Although the commercialization of the electromagnetic induction technology has been rapidly progressed around small-size devices, the power transmission distance is short.
Until now, wireless energy transmission schemes include a remote telecommunication technology based on resonance and a short wave radio frequency in addition to the electromagnetic induction.
Recently, among wireless power transmitting technologies, an energy transmitting scheme employing resonance has been widely used.
In a wireless power transmission system employing resonance, since an electrical signal generated between the wireless power transmitter and the wireless power receiver is wirelessly transferred through coils, a user may easily charge electronic appliances such as a portable device.
However, according to the related art, there is a limitation to reduce the power loss caused while AC power is converted into DC power in the wireless power receiver that receives power using resonance.